In the automobile industry, the application of the functional safety standards ISO 26262 and the compliance with the standards are being required in the development of electrical/electronic components and software of a microcomputer installed on the components. Automobile manufacturers and suppliers are constructing development environments that satisfy the requirements. In ISO 26262 Part 4 8.4.2 (hardware-software integration and testing), in principle, verification is required for all faults of all elements packaged on a printed wiring board by a real vehicle or by simulation. In fault insertion testing by real vehicles, it is difficult to cope with modes, such as a mode in which an ECU is broken one time and a mode in which the accumulation of electrical damage cases no reproducibility. Experiments are conducted on over 10,000 experimental items. Thus, real vehicle testing exerts a serious influence on man-hours, time periods, and costs. In such situations, methods of fault insertion testing using simulation-based virtual ECUs are being investigated.
Patent Literature 1 discloses a method (Method for Fault Analysis Using Simulation) in which faults in the open circuit and short circuit of electronic components are analyzed by simulation. According to the simulation method of Patent Literature 1, a model of a faulty ECU circuit is created by connecting variable resistors in series or in parallel. A circuit topology is changed for each fault for simulating the faulty ECU circuit.